Abstract: Objective To investigate the clinical characteristics and related factors of spontaneous hepatitis B surface antigen (HBsAg) clearance in inactive HBsAg carriers (IHCs). Methods IHCs in our hospital from January 2009 to December 2015 were enrolled and followed up at least once. None of the patients received any nucleoside analogues and/or interferon antiviral therapy. The differences between patients with and without spontaneous HBsAg clearance during follow-up were retrospectively analyzed. Results A total of 289 IHCs were enrolled in this study, including 161 males (55.71%) with an average age of 46.80 years. The alanine aminotransferase level was 21.40 ± 7.64 U/L, and serum HBsAg, hepatitis B envelope antigen (HBeAg) and hepatitis B virus deoxyribonucleic acid (HBV DNA) levels were 4592.00 (2262.00-6741.00) COI, 0.10 (0.09-0.12) COI and 430.05 (213.25-824.25) IU/mL, respectively. Serum HBsAg level was correlated with HBeAg level (r=1.86, P<0.01) and age (r=-1.82, P<0.01), but had no relationship with HBV DNA (r=0.09, P=0.58). During an average follow-up of 3 years, 17 patients (2.60%) had spontaneous HBsAg serological clearance, with an annual incidence of 0.87%. The serum levels of HBsAg, HBeAg and HBV DNA in patients with spontaneous HBsAg serological clearance were significantly lower than those in patients without (all P<0.01), but there were no significant differences in gender, age and liver function between the 2 groups. Conclusion There is no significant correlation between serum HBsAg and HBV DNA levels in IHCs. Patients with lower serum levels of HBsAg, HBeAg and HBV DNA are more likely to achieve spontaneous HBsAg serological clearance.

Key words: Inactive hepatitis B surface antigen carrier, Hepatitis B surface antigen titer, Spontaneous hepatitis B surface antigen seroclearance